Photoflash bomb

ABSTRACT

A photoflash bomb containing a metal powder, an oxidizing agent and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate isolated compartments, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being concentrically located with respect to said metal powder, and said explosive burster.

United States Patent [72] Inventors David Hart;

Henry J. Eppig, Dover; Garry Weingarten, Morris Plains, NJ. [21] Appl. No. 333,852 [22] Filed Jan. 28, 1953 [45] Patented Jan. 26, 1971 [73] Assignee T0 the United States of America as represented by the Secretary of the Army [54] PHOTOFLASH BOMB 10 Claims, 4 Drawing Figs.

[52] US. Cl 102/6, 102/66, 102/90 [51] F42b25/l4 [50] 102/60, 6, 90, 66, 87, 35, 35.2; 52/4, 24

[56] References Cited UNITED STATES PATENTS 735,299 8/ 1903 Reichemall 102/60X Primary Examiner-Verlin R. Pendegrass Att0rneyEdward J. Kelly ABSTRACT: A photoflash bomb containing a metal powder, an oxidizing agent and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate isolated compartments, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being concentrically located with respect to said metal powder, and said explosive burster.

The invention described herein may be manufactured and chemical components in such proportions, and having such chemical and physical characteristics, as to furnish a photoflash bomb of high efficiency, improved chemical stability, and practical acceptability to the armed forces.

Photoflash bombs are well known to be valuable in operations involving night aerial photography. For this purpose there have been employed photoflash bombs containing composite photoflash powders which are mixtures of oxidizing agents and metal powders. These compositions are very sensitive to impact, friction and static; and it has been found that because of such sensitivity they are hazardous to manufacture and load into bombs. Moreover the bombs that are loaded with such mixtures are liable to detonate upon impact or penetration by flak, bullets, or any projectile, or upon the occurrence of any emergency or accident, as the bomb is jettisoned or the plane carrying such bombs is compelled to crash land. 1

In overcoming these handicaps there has been developed a safe-type photoflash bomb in which there is contained a metal powder and a central explosive burster, composed of TNT or other relatively insensitive, centrally dispositioned explosive. This type of photoflash bomb has considerable advantages. However it has been found that this type does not yield as much light as the type containing a photoflash composition.

We have discovered that a photoflash bomb having the advantages of both the metal-oxidizer composition type, and the oxidizer-free type, can be obtained by employing an oxidizing agent, in segregated relationship to the metal powder. Upon activation of the bomb an explosive burster serves to break open the bomb, disperse, commingle and ignite the oxidizing agent and the metal powder, thus obtaining the desired effect of the photoflash composition mixture without the attendant hazards. We have further found that Your invention makes possible the joint use of metal powders and the oxidizing agents which hitherto could not be used in conjunction due to the fact they are mutually incompatible. We have further found that our invention makes possible the use of hygroscopic oxidants hitherto not practically usable. In loading the-latter resort may be had to appropriate dehumidifying apparatus.

Our invention is exemplified in a photoflash bomb containing a metal powder, an oxidizing agent, and an explosive burster, wherein said materials occupy separate compartments, suitable means being provided to retain the metal powder and oxidizing agent in segregated relationship.

In the forms herein illustrated and described our invention is directed to aphotoflash bomb having an outer portion containing a metal powder, an intermediate portion containing an oxidizing agent, and a central portion wherein is located an explosive burster charge.

To illustrate our invention we have chosen embodiments hereinafter fully set forth:

FIG. I is a view showing in part, a section along the longitudinal axis of a bomb, and showing also in elevation, a time fuse and a fin assembly. I

FIG. 2 is a view showing a cross section of the structure of bomb illustrated in FIG. I.

FIG. 3 is a view showing a cross section of a modification of the structure ,of bomb illustrated in FIG. 1 and FIG. 2.

FIG. 4 is a view showing a cross section of another modification ofthe structure of bomb illustrated in FIG. 1 and FIG. 2.

In the drawings, defines the wall of a container, comprising an outer compartment II, wherein'is carried a metal powder. In the embodiment shown in FIG. l and FIG. 2, there is provided a concentrically disposed intermediate compartment 12, containing an oxidizing agent; and in this embodiment, concentric to the outer compartment and to the intermediate compartment, a third concentric axially elongated central core 13, of an explosive burster charge, is located.

In FIG. 1 the central core 13, contained in a tube 14, is provided at the lower end with an adapter 15, for receiving and holding a time fuse 16, which may be of conventional design.

Normally the wall 10 will be formed of a relatively strong material, such as steel, which constitutes a casing for the contained materials. However, due to the reduced danger from damage to the bomb, in comparison with prior bombs, the wall may be relatively thin, thus effecting a saving in cost and weight. The intermediate and inner compartments may be formed of any material having requisite strength and passivity toward the materials that they contain. To this end thin metal or even cardboard may be employed.

The time fuse l6'may be of any suitable or known construction permitting a predetermined set or adjustment before the bomb is launched. In other respects the bomb may accord to any known or standard form and construction, and modifications thereof may be introduced without departing from the scope of my invention.

In the modification shown in FIG. 3 the oxidizing agent is carried in a plurality of elongated cylinders 17 concentrically disposed around and adjacent to the central core.

In the modification shown in FIG. 4, the oxidizing agent is carried in a plurality of elongated cylinders 17', concentrically disposed around the central core at a locus somewhat removed from the central core.

Any suitable metal powder may be used such, for example, as aluminum, magnesium, magnesium-aluminum alloy or iron. These metals may be employedsingly or in admixture, mixtures of aluminum and magnesium, for example, having been found satisfactory. The metal powder may be'in any suitable state of subdivision, good results having been obtained when the granulation of the powder is such as to pass a 200 mesh screen. It has been found that the particle shape of the metal powder can be such as to enable the cheaper types to be successfully employed. However, the metal powder used may be selected from any desired available types, such for example, as those wherein the particle type is designated as ground, flake, or atomized. By the term ground" we refer to metal powder that is furnished in the form of minute chips or attritus obtained from large solid chunks or bodies of the metal; by the term flake we refer to that powder which consists of vflat blades or leaves exemplified by the so-called bronze pigments" widely employed in paints and coating compositions; by the term atomized we refer to that type powder which is produced by a process of so-called atomization of molten metal whereby the particles acquire a spheroidal shape. Whereas the latter type has found preferential use in photoflash bombs, due to its resistance to pelleting and higher efficiency of illumination, in accordance with the present invention we have found that we are by no means restricted to the use of atomized metal powder in order to get good efficiency and higher satisfactory results. In accordance with our invention any suitable oxidizing agent may be used, and the following may be regarded as exemplary: perchlorates of sodium, potassium, ammonium, lithium, calcium, and magnesium; nitrates of sodium, potassium, barium, and strontium; peroxidesof barium, and strontium; bromine trifluoride; potassium chlorate, sulfuric acid and nitric acid. By the use of our novel construction, the range: of useful oxidizing agents is extended, inasmuch as incompatibilities, hygroscopicity, and other characteristics that are objectionable when the metal powder and the oxidizing agent are intermingled, are obviated by keeping the materials in segregated condition. It accordingly becomes possible to employ less costly oxidizing agents than otherwise could be employed.

A wide range of explosive materials for the central burster charge have been found suitable, notably trinitrotoluene, tritonal, RDX, tetryl, sodatol, black powder, pyrotechnic compositions, either singly, or jointly, or in admixture with additions of metal powder, such for example, as aluminum powder. By adhering to the construction in accordance with our invention the useful range of explosive materials has been extended for reasons given in the preceding description relating to the oxidizing agents, and more opportunity is afforded for selecting the explosive with a view to reducing costs.

In comparison with known flash bombs which have been found to reach peak illumination about 75 milliseconds after burst, or even longer, bombs constructed in accordance with our invention reach peak illumination intensity in about 25 to 50 milliseconds after burst. This characteristic is important inasmuch as the said shorter time of reaching peak intensity is better adapted to the requirements of camera shutters now employed in night aerial cameras.

Bombs constructed in accordance with our invention having a diameter of 4 inches and a length of '16 inches have displayed a peak luminous intensity as high as 250 to 900 million candles, and those having a diameter of 8. inches and a length of 35 inches, peak luminous intensities of l to 2 billion candles.

Having thus described the invention what is claimed as new We claim:

1. A photoflash bomb containing a metal powder, an oxidizing agent and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate iso lated compartments, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being concentrically located with respect to said metal powder, and said explosive burster.

2. A photot'lash bomb according to claim 1 wherein the oxidizing agent is contained in a single concentric annular compartment.

3. A photographic bomb according to claim 1 wherein the oxidizing agent is contained in a plurality of compartments concentrically located adjacent the centrally located explosive burster.

4. A photographic bomb according to claim 1 wherein the oxidizing agent is contained in a plurality of compartments concentrically located intermediate the centrally located explosive burster, and the outer wall of said bomb.

S. A photoflash bomb containing a metal powder, an oxidizing agent, and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate isolated concentric and coaxial compartment, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being intermediately located with respect to said metal powder, and fuze means to ignite said burster.

6. A photoflash bomb containing a metal powder selected from the class consisting of aluminum, magnesium, and iron, an oxidizing agent selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium and magnesium, nitrates of sodium, potassium, barium and strontium, peroxides of barium and strontium, potassium chlorate, sulfuric acid, and nitric acid, and an explosive burster selected from the class consisting of trinitrotoluene, tritonal, RDX, tetryl, sodatol, black powder, each of said classes of metal powder, oxidizing agent, and explosive burster occupying separate isolated compartment, within said bomb and fuze means to ignite said burster.

7. A photoflash bomb according to claim 6 wherein the metal powder particles are of spheroidal shape. 1

8. A photoflash bomb having an outer casing, a quantity of metal powder within said outer casing, said outer casing surrounding a closed container having a quantity of oxidizing agent therein, the metal powder and oxidizing agent thus maintained in segregated relation with respect to each other, an explosive burster charge within said outer casing segregated from said metal powder and said oxidizing agent for explosively intermixmg and igniting said metal pow er and oxidizing agent, and a fuze for initiating said explosive burster.

9. A photoflash bomb having an outer casing and including within said casing a quantity of metal powder, an explosive burster in a first container, and a segregated oxidizing agent in a second container selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium and magnesium, nitrates of sodium, potassium, barium and strontium peroxides of barium and strontium, potassium chlorate, sulfuric acid and nitric acid, both said first and second containers positioned within said outer casing.

10. A photoflash bomb having an outer casing, a quantity of metal powder within said outer casing, said outer casing surrounding a closed container having a quantity of oxidizing agent therein selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium, and magnesium, nitrates of sodium, potassium, barium and strontium, peroxides of barium and strontium, potassium chlorate, sulfuric acid and nitric acid, the metal powder and oxidizing agent thus maintained in segregated relation with respect to each other, an explosive burster charge within said outer casing segregated from said metal powder and said oxidizing agent for explosively intermixing and igniting said metal powder and oxidizing agent, and a fuze for initiating said explosive burster. 

1. A photoflash bomb containing a metal powder, an oxidizing agent and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate isolated compartments, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being concentrically located with respect to said metal powder, and said explosive burster.
 2. A photoflash bomb according to claim 1 wherein the oxidizing agent is contained in a single concentric annular compartment.
 3. A photographic bomb according to claim 1 wherein the oxidizing agent is contained in a plurality of compartments concentrically located adjacent the centrally located explosive burster.
 4. A photographic bomb according to claim 1 wherein the oxidizing Agent is contained in a plurality of compartments concentrically located intermediate the centrally located explosive burster, and the outer wall of said bomb.
 5. A photoflash bomb containing a metal powder, an oxidizing agent, and an explosive burster, each of said metal powder, oxidizing agent, and explosive burster occupying separate isolated concentric and coaxial compartment, said metal powder occupying an outer compartment, said explosive burster being centrally located, and said oxidizing agent being intermediately located with respect to said metal powder, and fuze means to ignite said burster.
 6. A photoflash bomb containing a metal powder selected from the class consisting of aluminum, magnesium, and iron, an oxidizing agent selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium and magnesium, nitrates of sodium, potassium, barium and strontium, peroxides of barium and strontium, potassium chlorate, sulfuric acid, and nitric acid, and an explosive burster selected from the class consisting of trinitrotoluene, tritonal, RDX, tetryl, sodatol, black powder, each of said classes of metal powder, oxidizing agent, and explosive burster occupying separate isolated compartment, within said bomb and fuze means to ignite said burster.
 7. A photoflash bomb according to claim 6 wherein the metal powder particles are of spheroidal shape.
 8. A photoflash bomb having an outer casing, a quantity of metal powder within said outer casing, said outer casing surrounding a closed container having a quantity of oxidizing agent therein, the metal powder and oxidizing agent thus maintained in segregated relation with respect to each other, an explosive burster charge within said outer casing segregated from said metal powder and said oxidizing agent for explosively intermixing and igniting said metal powder and oxidizing agent, and a fuze for initiating said explosive burster.
 9. A photoflash bomb having an outer casing and including within said casing a quantity of metal powder, an explosive burster in a first container, and a segregated oxidizing agent in a second container selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium and magnesium, nitrates of sodium, potassium, barium and strontium peroxides of barium and strontium, potassium chlorate, sulfuric acid and nitric acid, both said first and second containers positioned within said outer casing.
 10. A photoflash bomb having an outer casing, a quantity of metal powder within said outer casing, said outer casing surrounding a closed container having a quantity of oxidizing agent therein selected from the class consisting of perchlorates of sodium, potassium, ammonium, lithium, calcium, and magnesium, nitrates of sodium, potassium, barium and strontium, peroxides of barium and strontium, potassium chlorate, sulfuric acid and nitric acid, the metal powder and oxidizing agent thus maintained in segregated relation with respect to each other, an explosive burster charge within said outer casing segregated from said metal powder and said oxidizing agent for explosively intermixing and igniting said metal powder and oxidizing agent, and a fuze for initiating said explosive burster. 